Design of High-Efficient Bits for Igneous Rock in Xushen Gasfield

2013 ◽  
Vol 385-386 ◽  
pp. 308-311
Author(s):  
Li Gang Zhang ◽  
Tie Yan ◽  
Shi Bin Li
Keyword(s):  
Tungsten Carbide ◽  
Design Method ◽  
Polycrystalline Diamond ◽  
High Hardness ◽  
Rake Angle ◽  
Gas Field ◽  
Working Face ◽  
High Efficient ◽  
Low Efficiency ◽  
Bit Life

The igneous rocks in deep formations of the Xushen gasfield have the following characters: high abrasive property, high hardness, and high drillability, which lead to many drill bit accidents, few footage per bit , low efficiency of drilling, long drilling cycle, these severely restrict the exploration and development process of gas field. According to the features of deep formation, a hybird cutters bit is designed. It has three cones, with the overhang cone , duplicate taper and offset cone characters. The tungsten carbide cutters and the polycrystalline diamond compacts cutters are alternative collocation in the same tooth row in the bit. The exposed height of the tungsten carbide cutters is higher than polycrystalline diamond compacts cutters. The back rake angle of polycrystalline diamond compacts cutters is 10 ~ 40 °, the side rake angle is 10 ~ 30 °. The normal direction of working face stay the same with the composite slip direction, and the side rake pointed at adjacent gullet. Through the design method, it is integrated that the advantages of roller bit and PDC bit, the way of impact breakage and rotational shear breakage and the prominent performance of tungsten carbide cutters and polycrystalline diamond compacts cutters. It can improveROP and bit life.

Design and Study of PDC Bit for Igneous Rock Formation of Santanghu

2010 ◽  
Vol 156-157 ◽  
pp. 379-382
Author(s):  
Zhong Liang Wei ◽  
Jian Qun Zhang ◽  
Ji Tai Li ◽  
Ji Biao Xue ◽  
Yong Zhang
Keyword(s):  
Igneous Rock ◽  
Polycrystalline Diamond ◽  
High Hardness ◽  
Rake Angle ◽  
Design Methods ◽  
Optimized Design ◽  
Rock Stratum ◽  
Rock Formation ◽  
Crown Shape ◽  
Pdc Bit

Based on the geological configuration and formation lithology of igneous rock stratum of Santanghu, optimized design methods of PDC (polycrystalline diamond compact) bit are used to design PDC bit crown shape, cutting angle, the distribution of cutters and hydraulic structure, etc. Especially, these methods, which are design methods of gentle crown profile, spiral blade, high-density distribution of cutters, suitable back rake angle, and hydraulic structures which are more flexible nozzles of asymmetric arrangement and deeper fluid course layout, are fit for high hardness, multiple interbed and high abrasiveness of the igneous rock formation. The bit designed in this paper has turned out to be much better in the experiment of Horse 36 well of Santanghu.

Thermally induced defects in a polycrystalline diamond layer on a tungsten carbide substrate

2009 ◽  
Vol 404 (22) ◽  
pp. 4485-4488 ◽  
Author(s):  
B.N. Masina ◽  
A. Forbes ◽  
O.M. Ndwandwe ◽  
G. Hearne ◽  
B.W. Mwakikunga ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Polycrystalline Diamond ◽  
Thermally Induced ◽  
Diamond Layer ◽  
Induced Defects

scholarly journals Mechanism and Prevention and Control of Mine Earthquake in Thick and Hard Rock Strata considering the Horizontal Stress Evolution of Stope

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Ming Zhang ◽  
Xuelong Hu ◽  
Hongtao Huang ◽  
Guangyao Chen ◽  
Shan Gao ◽  
...  
Keyword(s):  
Hard Rock ◽  
Design Method ◽  
Horizontal Stress ◽  
Prevention Measures ◽  
Stress Concentrations ◽  
Estimation Model ◽  
Working Face ◽  
Mining Design ◽  
And Control ◽  
Rock Strata

This study investigated the mechanism, prevention measures, and control methods for earthquake disasters typically occurring in mines with thick and hard rock strata. A mine stope with large faults and thick hard rock strata in Hebei Province was taken as the background study object. Then, theoretical analysis and numerical simulation methods were adopted in conjunction with field monitoring to explore how horizontal stress evolves in the thick and hard hanging roofs of such mines, potentially leading to mining earthquakes. Then, based on the obtained results, a mining design method was proposed to reduce the horizontal stress levels of earthquake mitigation. The results showed that, under the control of large faults, semiopen and semiclosed stopes with thick hard rock strata are formed, which cause influentially pressurized and depressurized zones during the evolution of the overburden movements and horizontal stress. It was determined that the stress concentrations mainly originated from the release and transfer of horizontal stress during the rock fractures and movements in the roof areas, which were calculated using a theoretical estimation model. The horizontal stress concentrations formed “counter torques” at both ends of the thick and hard strata, which prevented the support ending due to tensile failures. As a result, the limit spans were increased. This study proposed a mining strategy of using narrow working faces, strip mining processes, and reasonable mining speeds, which could effectively reduce horizontal stress concentrations and consequently prevent and control mining earthquakes. This study’s research results were successfully applied to the mining practices in working face 16103.

scholarly journals Technological Shells in the Processes of Rolling Thin Sheets From Hard-To-Deform Materials

2021 ◽  
Author(s):  
Denis R Salikhyanov ◽  
Ivan Kamantsev
Keyword(s):  
Stress State ◽  
Tool Steel ◽  
Process Parameters ◽  
Fe Simulation ◽  
Rolling Force ◽  
High Hardness ◽  
Thickness Variation ◽  
Rolled Sheet ◽  
Total Reduction ◽  
Low Efficiency

Abstract The present work is devoted to the study of deformability of high-strength and hard-to-deform materials. Today the most promising technology for their forming is a rolling in a ductile shell also known as sandwich rolling. Despite the fact that the use of such technological shells allows to effectively reduce the rolling forces and soften the stress state, they have not got wide application in manufacturing practice due to the accompanying disadvantages. On the basis of finite element (FE) simulation, we carried out an all-around analysis of the effect of shell material on process parameters of method: rolling force, total reduction of hard-to-deform material, deformation inhomogeneity and thickness variation of rolled sheet, stress state scheme. Analysis of computer models allowed us to highlight the main reason for the low efficiency of the known method and propose a new design of technological shells. Preliminary FE-simulation of the rolling process of hard-to-deform material in the new technological shells showed an improvement in process parameters and method efficiency. Approbation was carried out via rolling U12 high-carbon tool steel (Russian analogue of DIN C110W2 tool steel), which has low plasticity and high hardness, on the rolling mill Duo 250 under laboratory conditions. Evaluation according to technological criteria – reducing the rolling force, increase of the total reduction and the deformation uniformity of hard-to-deform material, improvement of its deformability – showed the prospects of using proposed technological shells in manufacturing practice.

Manufacturing and Properties of Tungsten Carbide-Oxide Composites

2017 ◽  
Vol 742 ◽  
pp. 223-230 ◽  
Author(s):  
Anne Vornberger ◽  
Johannes Pötschke ◽  
Christian Berger
Keyword(s):  
Mechanical Properties ◽  
Tungsten Carbide ◽  
Metal Content ◽  
High Hardness ◽  
Metal Carbide ◽  
Hard Materials ◽  
Binder Free ◽  
Oxide Composites ◽  
Hardness Values ◽  
Binder Metal

Conventional WC-Co hardmetals are widely used in various applications due to their excellent properties. High hardness can be achieved using compositions with little to no content of cobalt or nickel. These binder metals are hazardous to health, making a substitution not only desirable because of availability and cost reasons. A new possibility to manufacture such hard materials is the combination of tungsten carbide with oxides such as Al2O3 and ZrO2. In this way the binder metal content can be replaced. Furthermore the content of the also expensive WC can be reduced. Such metal carbide – oxide composites with oxide contents between 16 vol% and 40 vol% were manufactured. The completely dense composites feature high hardness values of 2000 HV10 to 2400 HV10 while also having an acceptable fracture toughness of up to 7 MPa⋅m1/2. The improved mechanical properties make the replacement of WC-Co hardmetals and binder free WC ceramics in special areas possible.

Mathematical Modeling of PDC Bit Drilling Process Based on a Single-Cutter Mechanics

1993 ◽  
Vol 115 (4) ◽  
pp. 247-256 ◽  
Author(s):  
A. K. Wojtanowicz ◽  
E. Kuru
Keyword(s):  
Polycrystalline Diamond ◽  
Rock Properties ◽  
Drilling Process ◽  
Drilling Parameters ◽  
Pdc Bit ◽  
Analytical Development ◽  
Assumed Similarity ◽  
Balance Of Forces ◽  
Bit Life ◽  
Polycrystalline Diamond Compact

An analytical development of a new mechanistic drilling model for polycrystalline diamond compact (PDC) bits is presented. The derivation accounts for static balance of forces acting on a single PDC cutter and is based on assumed similarity between bit and cutter. The model is fully explicit with physical meanings given to all constants and functions. Three equations constitute the mathematical model: torque, drilling rate, and bit life. The equations comprise cutter’s geometry, rock properties drilling parameters, and four empirical constants. The constants are used to match the model to a PDC drilling process. Also presented are qualitative and predictive verifications of the model. Qualitative verification shows that the model’s response to drilling process variables is similar to the behavior of full-size PDC bits. However, accuracy of the model’s predictions of PDC bit performance is limited primarily by imprecision of bit-dull evaluation. The verification study is based upon the reported laboratory drilling and field drilling tests as well as field data collected by the authors.

Forming Fine V-Grooves on a Tungsten Carbide Workpiece with a PCD Electrode by EDM

2007 ◽  
Vol 329 ◽  
pp. 631-636 ◽  
Author(s):  
Sadao Sano ◽  
Kiyoshi Suzuki ◽  
Wei Li Pan ◽  
Manabu Iwai ◽  
Yoshihiko Murakami ◽  
...  
Keyword(s):  
Tungsten Carbide ◽  
Pulse Duration ◽  
Flat Surface ◽  
Short Pulse ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Chemical Vapor Deposition Diamond ◽  
Electrically Conductive ◽  
Short Pulse Duration ◽  
Low Wear

Polycrystalline diamond (PCD) exhibits a thermal conductivity similar to that of the electrically conductive chemical vapor deposition diamond (EC-CVD diamond) found to function as zero-wear electrodes at short pulse duration. In this study, PCD was used as electrodes applied to EDM on tungsten carbide. Two kinds of PCD (CTB-010 and CTH-025) with a flat surface were used. The wear of the PCD electrodes was about 1.5% for very short pulse duration such as te=1μs, but it was zero wear at te=30μs, though the wear of a Cu-W electrode was 10% even on the machine recommended conditions for the low wear. EDM experiment using a V-shaped PCD electrode with an included angle of 45° was also carried out and the performance was compared with the case using a V-shaped Cu-W electrode. Under the conditions of a no load voltage of 60V, a set peak current of 2A, and a medium pulse duration of te=15μs, there was no wear on PCD electrodes when observed under the SEM, whereas a 50μm-deep wear on the Cu-W electrodes even under the machine recommended condition for the low wear was observed.

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